Slot Definition Guide

Looking for a particular slot definition? Before you hit the machines, think about learning the lingo. The more you know, the more you can learn.

Buy-a-Pay
These types of machines can be confusing to players. Each coin played activates a set of jackpot symbols, so basically, you are buying additional symbols. For example, you might insert one coin and three 7s might show up on the center payline, but you would not win a thing, because you did not pay for the 7s. It is especially important to play the maximum number of coins on these machines. If on the side of the machine you see a different combination of winning symbols when a second coin is played, it’s a buy-a-pay.

Coin-In
Slot machines have a meter that totals the amount of money played. As the term might suggest, it is the amount of coins you put in the machine. Casino managers use this meter to determine which machines are getting the most play and what their hold percentages are.

Coin Size
This refer to the size of each bet, or the number of coins you play for a particular spin.

Hit Frequency
Frequency is simply the percentage of spins that will return something to the player. A machine with a high hit frequency might sound good, but a hit doesn't necessarily mean a win. If, for example, you play three coins on every play and always win two coins, you are still in the hole, even though the hit frequency is 100%. Over the long run, if you add up the payouts each time the machine hits and divide it by the coin-in, the number will correspond closely with the payout percentage.

Hold Percentage
This is the percentage of money played that is kept by the casino - the opposite of the return or payout percentage.

Hopper
This is where the coins are held in the machine. Hoppers can be filled to overflowing by players, or they may run empty. Excess coins drop into a bucket underneath the hopper, which the casino takes as profit, and empty hoppers are refilled by staff.

Loose Machine
A loose slot machine, being the opposite of tight, returns more to players over the long term compared to other similar denomination slot machines.

Max Bet
The maximum number of coins that can be played in a spin.

Multipliers
This term refers to slot machines that multiply the payout in a successful hit by the number of coins played. The jackpot is the exception.

Nudge
This is a type of machine that, once the reels stop spinning, symbols will move to the center payline from just above or below it. You could, therefore, end up with a winning play even if no winning symbols appeared to begin with.

One-armed Bandit
Another name for a slot machine.

Pay Cycle
This slot definition may sometimes be used, but it does not necessarily reflect a real phenomenon. A pay cycle refers to a period of time following a minimum number of plays during which the machine pays out coins in larger percentages. However, an RNG, according to manufacturers, is not designed this way. Instead, they are designed to randomly generate numbers with the same odds consistently at any given moment, so that over the long run, the chances of payout reflect a certain percentage. See RNG below for further explanation.

Payline
Most slot machines have a single (though some have multiple) horizontal line at the middle of the visible reel area. This is where you want the proper symbols to line up in order to be paid.

Pay Table
The table found on the side of a slot machine or on the help screen listing the winning combinations.

Progressives
A progressive slot machine takes a percentage of all the coins that are played and adds it to a jackpot that increases in value. When the winning jackpot symbols are hit, some lucky player will win big. These machines are linked to other machines, often in different casinos, and thus, the jackpots may exceed several million dollars. The odds of winning on one of these machines, however, are much lower than on typical machines.

Reels
The reels of a slot machine are the cylindrical spinning objects on which all of the symbols are displayed. Most slot machines usually have three reels but sometimes you will find a two reel, four reel or higher. In a machine with a greater number of reels and a single jackpot line, your chances of hitting the right combination are less.

RNG
This slot definition is important for dispelling many myths about slot machines. RNG stands for random number generator and refers to the computer program that determines which symbols line up on the reels. Its purpose, as the name might suggest, is to generate a sequence of random numbers in milliseconds. Each random number it generates corresponds to a reel combination. If you happen to be lucky enough to make your move the exact moment that the RNG generates a number corresponding to a jackpot combination, you can thank pure chance for your good fortune (unless you have telekinetic and/or precognitive abilities). For more information on RNGs, check out our The Slot Machine Secret: The RNG section.

Return Percentage or Payout Percentage
Casinos will often brag about this number. It is the percentage of money put into the machine that comes back out. This does not mean that you will get $98 out if you put in $100, only that in the long run, after many hours of play, by many people, the machine will return 98% of what was put into it. As a general rule, the higher the denomination of machine, the greater the payout percentage.

Take Cycle
This is the opposite of the pay cycle, but again, this slot definition is, according to experts, hogwash. See Pay Cycle and RNG above for explanation.

Tight Machine
The opposite of a loose machine. A tight slot machine is one that has a lower payout percentage compared to other machines of the same denomination.

Top Prize
The top payout on non-progressive slots when playing the maximum number of coins.

Volatility
Slot manufacturers provide casino managers with a slot machine's volatility index, which refers to irregularities with a machine’s hold percentage, and casino managers use this number to determine whether or not the a machine is in line with expectations. If a machine pays out a lot more or a lot less than it is supposed to over a period of time, it is considered to have high volatility and it might be investigated. Volatility is expected to decrease as more games on the machine are added to the equation. In the short term, your results are likely to be very different from a machine's theoretical payout percentage.

Wild Pay
This refers to a type of slot machine where you have a chance to increase by two, three, five or 10 times the payout if a wild symbol lines up on the pay line. If more than one wild symbol lines up, the payout is multiplied.

Wild Symbol
A symbol that counts as any other symbol, similar to how a joker might be wild in poker. On some slot machines these symbols also multiply your winnings.

Now that you’ve learned any slot definition that you could possibly need to know, it’s time to hit the machines! Try our free machine here to practice your new slot definition knowledge, or lay some money on the line here.